Summary:

Any powered redstone dust (of any power state) will cause an observer to give an update when reloading a world

Steps to Reproduce:

-Place an observer with the detection end facing a powered redstone dust

-Attatch a system to the other end of the observer such that you can tell if it has been activated (Piston pushing up a block works well)

-Reload the world

Observed Results:
-The piston has been activated and the block extended (the observer activates)

Expected Results:
-There is no change in the redstone dust therefore no update should be given

Screenshots/Videos attached:
Notice Observer Obsidian location
Another Example

Notes:

This only seems to happen for redstone dust, no other components.

This has serious implications for even basic redstone contraptions and needs to be looked into.